Facility Core: Inhalation Exposure Facility, UTMB. Successful completion of the proposed ARCH program is critically dependent on the exposure of both whole animal models and in vitro cell culture systems to 1,3-butadiene. UTMB has recently completed construction of state-of-the-art facility which enables tightly controlled exposures of laboratory rodents and model systems to gases and vapors. The facility contains animal exposure chambers; a CO2 incubator equipped with glass isolation chambers; air handling systems for supply air production and exhaust gas removal; equipment for pollutant generation, mixing, and delivery, gas phase analysis equipment for chamber and in vitro system monitoring; and an animal holding room containing an HEPA fiber isolation unit. The exposure system incorporates default safety measures to ensure protection of both laboratory personnel and animals. Exposure protocols must first receive approval from both the Animal Care and Use Committee and for studies proposed under all three UTMB R-01 projects and two of the initial pilot projects to be conducted by Southern University. In addition, the facility will offer a hands-on training opportunity for both faculty and students at Southern University to learn fundamental principles of inhalation toxicology.